Is it possible change TVStandard without restarting X? (Maybe with NV-CONTROL?)

Hello,

I have a running, good working twinview configuration (LCD + PAL TV) and I know how to switch the TV-Standard between NTSC/PAL etc. by the TVStandard-Option in xorg.conf/XF86Config.

I would like to switch between NTSC/PAL on the fly , that means without restarting the X-server.

I have already found something that's called dynamic twinview: With the
NV-CONTROL X-Extension (that's also used by nvidia-settings) you can add twinview metamodes at runtime and then select them by xrandr. But I didn' t find a way to set the TVStandard of such newly created metamodes.